Well, Yosemite is off limits for visitation right now. I previously owned a ranch south of Yosemite near a lot of dogwoods. In that part of the world, it's a mid-elevation species between 4,000 to 6,000 ft., with blossom time typically May to June.
That's always been one of my favourite AA photos, saw it in real life in LA a few years ago, one of the most perfect "whites" I have ever seen in a photo. I've been toying with the idea of getting a print from the AA trust from his neg, printed by someone else.
I have "Dogwood Blossoms" on the wall of my little office just behind the computer station. It is the first Ansel Adams photograph I acquired. That was almost 30 years ago. It is a delight to gaze at it.
The catalogue listing for this photograph calls it simply "Dogwood" and omits "Blossoms". Other details:
Neg# 3-C-49
Format 5x7
Lens 7" Goerz Dagor
Film Type Agfa S
Dev N+1
Date 1938